KEO 53511 Cobalt Steel Single-End Countersink, Uncoated (Bright) Finish, 82 Degree Point Angle, Round Shank, 1/4" Shank Diameter, 3/8" Body Diameter

I bought the single flutes for countersinking steel based on the adviser of Brian House from YouTube as I was building his grinder and teaching myself to MIG weld. He said that they were the only ones he's had that don't chatter and leave faceted bevels. I have plenty of experience with countersink bits chattering, especially in steel, so I was delighted that these lived up to their billing. They aren't cheap, but they do a great job, even with a 15-year old Ryobi drill press. The secret is the single flute, which puts a minimum load on the press or mill, ensuring a smooth cut. Highly recommended.

I work with audio and other enclosures that require my drilling holes for switches, binding posts, RCA jacks and numerous other type connectors in aluminum and steel plates. A countersink is what I use to deburr the edges and provide a slight bezel for a polished look when some holes are exposed. I needed a new countersink and this one fit the bill perfectly. It provides a nice clean cut and perfect edge. Since it's made of cobalt, it hard and sharp. You can't go wrong with this if you're deburring and finishing small holes. Recommended.

If you look at the cutting head compared to the 1/4" shank, it is a much bigger one than 3/8 which it is supposed to be. So I don't appreciate the seller using deception to trick people into buying it

I’m throwing away all my current multi-fluted countersink bits because this one reigns supreme! Absolutely no rough edges and no tear out, even in plywood and veneers. Cuts ultra cleanly and super smooth. Don’t waste your time on drill/countersink combo bits. They’ll never achieve the result that this thing does. Would highly recommend.

I bought this for woodworking. I've worn out countersinks and have tried some that did nothing but generate heat and noise. This one cuts effortlessly. The chip hole does fill up, but easily clears. Ordered another in a larger size..

Cuts smooth uniform countersinks/champhers in wood. Eliminates the chatter marks you get using fluted bits.

This is the fastest, smoothest cutting countersink I’ve ever used. It is sized to countersink #4-#14 screws, which covers ever size I can imagine using. It removes the unwanted metal in a single ribbon, fast and simple. No chips, no mushrooming. I have no idea what more a person could ask for.

This is an awesome little tool. I can't believe how smooth of a cut it made in plywood. Very professional. It's a nice tool for getting screws seated in stock for a more finished look.It comes in a little red case that's a bit hard to open. It's small, and Amazon just tossed it in a box - I almost missed it and threw it out. But that's on Amazon's shipping, no fault in this product.I'm curious how long it will stay sharp and how hard it will be to sharpen.